Method for comprehensively judging single-phase disconnection fault of medium-voltage power distribution network

The invention, which relates to the technical field of the power grid fault, discloses a medium-voltage power distribution network single-phase disconnection fault comprehensive discrimination method comprising the following steps of S1, collecting three-phase voltage and current at a measurement point; s2, acquiring three-phase voltage and current amplitudes; s3, judging whether one of the three-phase voltages rises and the other two-phase voltages drops or not, if so, going to the step S4, and if not, returning to the step S1; s4, judging whether the phase current of the voltage rising phase is 0 or not or whether the break variable of the phase current is smaller than 0 or not, if yes, executing the step S5, and if not, returning to the step S1; s5, calculating to obtain a negative sequence impedance angle of the line; s6, judging whether the negative sequence impedance angle is within a preset range or not, if yes, judging that a broken line fault occurs and executing the step S7, and if not, returning to